PCA9534: multiple interrupt

nagaraj G H

Part Number: PCA9534
Other Parts Discussed in Thread: TCA9534

Hi,

We are having a issue with PCA9534 I/O Expander. Before we configured the i/o port, during initialization we are reading the input port register to clear interrupt pin,when interrupt occur in ISR we are reading the port status, but we are getting multiple interrupts, the interrupt which occurs for the second time has a longer interrupt duration. As per the datasheet after reading the port status (Register 0x00h) we are reading configuration register to avoid improperly de-asserted interrupt pin. we even tried by reading the polarity inversion register but the results are same.

We cannot change the I/O expander as the hardware is finalized. We need a software solution to over come this multiple interrupt issue.

Thanks,

Nagaraj

over 6 years ago

0 BOBBY over 6 years ago

TI__Mastermind 49040 points

Hey Nagaraj,

Do you have a schematic you could post so we can verify the device is set up properly?

Also, is it possible for you to switch from the PCA9534 to the TCA9534? Our TCA family is an upgrade from the PCA line and fixes some of the issues from the PCA series. (It looks like the PCA9534 has INT errata) Typically our TCA line is P2P replacement to the PCA line as well.

Thanks,

-Bobby

0 BOBBY over 6 years ago

TI__Mastermind 49040 points

Hey Nagaraj,

I wanted to check up and see if you were able to give our TCA line a shot and if you still needed support on this matter.

-Bobby

0 nagaraj G H over 6 years ago in reply to BOBBY

Intellectual 480 points

Hi Bobby,
Thanks for suggesting, we changed PCA9534 to TCA9534 as you suggested above,its working fine
Thanks,
-Nagaraj

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PCA9534: multiple interrupt